[MachineOutliner] Recommit r312194, missed optimization remarks
Before, this commit caused a buildbot failure:
http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/6026/steps/test_llvm/logs/LLVM%20%3A%3A%20CodeGen__AArch64__machine-outliner-remarks.ll
This was caused by the Key value in DiagnosticInfoOptimizationBase being
deallocated before emitting the remarks defined in MachineOutliner.cpp. As of
r312277 this should no longer be an issue.
llvm-svn: 312280
diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index 9a8eebf..c120354 100644
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -46,6 +46,7 @@
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/Support/Allocator.h"
@@ -64,6 +65,7 @@
#define DEBUG_TYPE "machine-outliner"
using namespace llvm;
+using namespace ore;
STATISTIC(NumOutlined, "Number of candidates outlined");
STATISTIC(FunctionsCreated, "Number of functions created");
@@ -895,8 +897,41 @@
size_t OutliningCost = CallOverhead + FrameOverhead + SequenceOverhead;
size_t NotOutliningCost = SequenceOverhead * Parent.OccurrenceCount;
- if (NotOutliningCost <= OutliningCost)
+ // Is it better to outline this candidate than not?
+ if (NotOutliningCost <= OutliningCost) {
+ // Outlining this candidate would take more instructions than not
+ // outlining.
+ // Emit a remark explaining why we didn't outline this candidate.
+ std::pair<MachineBasicBlock::iterator, MachineBasicBlock::iterator> C =
+ CandidateClass[0];
+ MachineOptimizationRemarkEmitter MORE(
+ *(C.first->getParent()->getParent()), nullptr);
+ MachineOptimizationRemarkMissed R(DEBUG_TYPE, "NotOutliningCheaper",
+ C.first->getDebugLoc(),
+ C.first->getParent());
+ R << "Did not outline " << NV("Length", StringLen) << " instructions"
+ << " from " << NV("NumOccurrences", CandidateClass.size())
+ << " locations."
+ << " Instructions from outlining all occurrences ("
+ << NV("OutliningCost", OutliningCost) << ")"
+ << " >= Unoutlined instruction count ("
+ << NV("NotOutliningCost", NotOutliningCost) << ")"
+ << " (Also found at: ";
+
+ // Tell the user the other places the candidate was found.
+ for (size_t i = 1, e = CandidateClass.size(); i < e; i++) {
+ R << NV((Twine("OtherStartLoc") + Twine(i)).str(),
+ CandidateClass[i].first->getDebugLoc());
+ if (i != e - 1)
+ R << ", ";
+ }
+
+ R << ")";
+ MORE.emit(R);
+
+ // Move to the next candidate.
continue;
+ }
size_t Benefit = NotOutliningCost - OutliningCost;